Low serum folate levels as a risk factor for depressive mood in patients with chronic epilepsy

Is Depression Related to Low Folate Levels in People with Epilepsy? An Observational Study and Meta-analysis

Background:

Both depression and low serum levels of folate are common in people with epilepsy (PWE), the latter especially in patients on hepatic enzyme-inducing antiepileptic drugs (AEDs). We did a cross-sectional study and a meta-analysis to assess if lower folate levels have any relation with depression in PWE.

Materials and Methods:

Two hundred and one PWE were recruited and assessed for depression using the Inventory of Depressive Symptomatology-Self-Rated (IDS-SR) and Inventory of Depressive Symptomatology-Clinician Rated; serum folate levels were measured in them at the same time. Literature search was carried out and studies with data on depression as well as folate levels in PWE were included. Statistical analysis to determine frequency of depression, low folate levels, and relation between them among our cases and the pooled data from the included studies was done.

Results:

Depression was observed in 65.68% and low serum folate (<4 ng/ml) in 48.75% of PWE (over 80% on older AEDs); there was no statistically significant correlation between them. However, on analyzing the pooled data of six studies including the present, the Fisher's z-transformed correlation coefficient was −0.1690 (95% confidence interval [−0.3175, −0.0124], P = 0.0464).

Conclusions:

Depression and low folate levels are common in PWE. Low folate levels have a mild but significant negative correlation with depression in this population, and folate supplementation would be advisable for those on the older AEDs.

The effect of vitamin B supplementation on homocysteine metabolism and clinical state of patients with chronic epilepsy treated with carbamazepine and valproic acid

PURPOSE

To investigate the influence of vitamin B supplementation on the plasma total homocysteine (p-tHcy), serum folate (s-FA), serum B12 (s-B12), and clinical state of patients with chronic epilepsy.

METHODS

Beck Depression Inventory (BDI) scores and p-tHcy, s-B12, and s-FA levels were assessed at baseline, after 1 year of supplementation (G1), and before and after 1 year of VPA or CBZ therapy (G2).

RESULTS

Eighty-one patients participated in the study: 51 patients with chronic epilepsy (G1) treated with carbamazepine (CBZ) or valproic acid (VPA), and 30 patients with newly diagnosed epilepsy (G2). At baseline, mean p-tHcy level was significantly higher in G1 than G2 (p=0.0001) with no significant differences in s-FA or s-B12 levels. p-tHcy level significantly decreased in CBZ-treated G1 patients (p=0.00002) after 1 year of supplementation and increased in G2 after 1 year of anti-epileptic drug (AED) therapy without supplementation. BDI scores in G1 decreased significantly after 1 year of supplementation (p=0.0001) and increased significantly in VPA-treated G2 patients after 1 year of AED therapy (p=0.02). The number of hyperhomocysteinemic patients significantly decreased in G1 after vitamin B supplementation (p=0.01) and increased in G2 (p=0.002). We also observed improved BDI scores and reduced seizure frequency in patients with chronic epilepsy.

CONCLUSIONS

These data support the hypothesis that AEDs play a major role in hyperhomocysteinemia development in patients with epilepsy. Adding folate and vitamin B12 to AED therapy is a safe and inexpensive way to reduce the risk of hyperhomocysteinemia.

Association of epilepsy and comorbid conditions

Comorbid health conditions are common among people with epilepsy. Proposed explanations for this association include the possibility that first, epilepsy (including its treatment) causes the comorbid condition; second, the comorbid condition (including its treatment) causes epilepsy; or third, a common pathogenic mechanism mediates the co-occurrence of epilepsy and the comorbid condition. It is unlikely that a single explanation will suffice for all of the epilepsy comorbid conditions. Determining the basis of the association between epilepsy and its comorbid conditions has important implications for diagnosis and management. In this paper, we discuss this issue in the context of five common epilepsy comorbid conditions: bone health and fractures, stroke, depression, migraine and attention-deficit hyperactivity disorder. Current findings, research limitations and future directions of research efforts are discussed.

Declines in dietary macronutrient intake in persons with HIV infection who develop depression

Background

The effect of depression on dietary intake has not, to our knowledge, been examined in persons with HIV infection.

Methods

We conducted a longitudinal analysis of participants in the Nutrition for Healthy Living Study (NFHL). We measured changes in dietary macronutrient intake in participants who developed depression and, using multiple regression analysis, compared the changes with a control group of patients who did not become depressed.

Results

Ninety patients developed depression during the observation period, and we compared these with 152 non-depressed controls. The two groups had similar age and body mass index (BMI) at baseline, but those who developed depression were more likely to be female, less educated and had lower incomes. After adjustment, compared with non-depressed participants, those who developed depression had significantly greater decreases in the following daily intakes: total energy (−341 kcal, P = 0.006), protein (−12.3 g, P = 0.02), total fat (−18.5 g, P = 0.008), carbohydrate (−36.8 g, P = 0.02), total fibre (−4.3 g, P = 0.001) and saturated fat (−6.7 g, P = 0.01). There were no significant differences in the daily intakes of simple sugars and long-chain n−3 fatty acids, or BMI.

Conclusion

Depression is associated with decreases in total daily energy intake and in six of the eight dietary components we measured. Clinicians should be aware that depression-associated nutritional deficiencies may complicate the care of persons with HIV.

Is low folate a risk factor for depression? A meta-analysis and exploration of heterogeneity

Low folate has been causatively linked to depression, but research is contradictory. An association may arise due to chance, bias, confounding or reverse causality. A systematic review of observational studies which examined the association between depression and folate was conducted. 11 relevant studies (15 315 participants; three case-control studies, seven population surveys and one cohort study) examining the risk of depression in the presence of low folate were found. Pooling showed a significant relationship between folate status and depression (odds ratio (OR)(pooled unadjusted) = 1.55; 95% CI 1.26 to 1.91). This relationship remained after adjustment for potential confounding (OR)(pooled adjusted) = 1.42; 95% CI 1.10 to 1.83). Folate levels were also lower in depression. There is accumulating evidence that low folate status is associated with depression. Much of this evidence comes from case-control and cross-sectional studies. Cohort studies and definitive randomised-controlled trials to test the therapeutic benefit of folate are required to confirm or refute a causal relationship.

Nutrition and depression: implications for improving mental health among childbearing-aged women

Adequate nutrition is needed for countless aspects of brain functioning. Poor diet quality, ubiquitous in the United States, may be a modifiable risk factor for depression. The objective was to review and synthesize the current knowledge of the role of nutrition in depression, and address implications for childbearing-aged women. Poor omega-3 fatty acid status increases the risk of depression. Fish oil and folic acid supplements each have been used to treat depression successfully. Folate deficiency reduces the response to antidepressants. Deficiencies of folate, vitamin B12, iron, zinc, and selenium tend to be more common among depressed than nondepressed persons. Dietary antioxidants have not been studied rigorously in relation to depression. Childbearing-aged women are particularly vulnerable to the adverse effects of poor nutrition on mood because pregnancy and lactation are major nutritional stressors to the body. The depletion of nutrient reserves throughout pregnancy and a lack of recovery postpartum may increase a woman's risk of depression. Prospective research studies are needed to clarify the role of nutrition in the pathophysiology of depression among childbearing-aged women. Greater attention to nutritional factors in mental health is warranted given that nutrition interventions can be inexpensive, safe, easy to administer, and generally acceptable to patients.

Plasma folate and homocysteine levels may be related to interictal "schizophrenia-like" psychosis in patients with epilepsy

Genetic and clinical data suggest that folate and homocysteine may play a role in the pathogenesis of psychiatric disorders. The total plasma homocysteine level is a sensitive measure of a functional folate deficiency. We thus investigated whether a functional folate deficiency and/or elevated levels of plasma homocysteine may be related to interictal "schizophrenia-like" psychosis (interictal psychosis ) of epilepsy. We studied the plasma folate, vitamin B12, and homocysteine levels of 32 age- and sex-matched epileptic patients with or without interictal psychosis. Each group included 25 localization-related epilepsies and 7 generalized epilepsies. The epileptic patients with interictal psychosis had significantly lower folate levels and higher homocysteine levels than those without interictal psychosis. There were no significant differences in the vitamin B12 levels between the two groups. The present study suggests that low plasma folate and high plasma homocysteine levels may be related to the pathophysiology of interictal psychosis of epilepsy. In future studies, we should investigate whether folate supplementation, in addition to antipsychotics, might play a beneficial role in the treatment of interictal psychosis in epileptic patients. Furthermore, the present findings should be confirmed by prospective longitudinal studies in a larger group of patients with epilepsy.

Treatment of depression: time to consider folic acid and vitamin B12

We review the findings in major depression of a low plasma and particularly red cell folate, but also of low vitamin B12 status. Both low folate and low vitamin B12 status have been found in studies of depressive patients, and an association between depression and low levels of the two vitamins is found in studies of the general population. Low plasma or serum folate has also been found in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similarly been found in patients with alcoholism. It is interesting to note that Hong Kong and Taiwan populations with traditional Chinese diets (rich in folate), including patients with major depression, have high serum folate concentrations. However, these countries have very low life time rates of major depression. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants. A recent study also suggests that high vitamin B12 status may be associated with better treatment outcome. Folate and vitamin B12 are major determinants of one-carbon metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates methyl groups that are crucial for neurological function. Increased plasma homocysteine is a functional marker of both folate and vitamin B12 deficiency. Increased homocysteine levels are found in depressive patients. In a large population study from Norway increased plasma homocysteine was associated with increased risk of depression but not anxiety. There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the MTHFR C677T polymorphism that impairs the homocysteine metabolism is shown to be overrepresented among depressive patients, which strengthens the association. On the basis of current data, we suggest that oral doses of both folic acid (800 microg daily) and vitamin B12 (1 mg daily) should be tried to improve treatment outcome in depression.

The influence of folate serum levels on depressive mood and mental processing in patients with epilepsy treated with enzyme-inducing anti-epileptic drugs

BACKGROUND

Folate deficiency is common in patients with epilepsy and also occurs in patients with depression or cognitive deficits.

OBJECTIVE

This study investigates whether low serum folate levels may contribute to depressive mood and difficulties in mental processing in patients with epilepsy treated with anti-epileptic drugs inducing the cytochrome P450.

METHODS

We analysed the serum folate levels, the score in the Self Rating Depression Scale (SDS) and the results of a bedside test in mental processing in 54 patients with epilepsy.

RESULTS

There was a significant negative correlation between the serum folate levels and the score in SDS and significant positive correlations between the score in SDS and the time needed to process an interference task or a letter-reading task.

CONCLUSIONS

Low serum folate levels may contribute to depressive mood and therefore to difficulties in mental processing. Further studies utilizing total plasma homocysteine as a sensitive measure of functional folate deficiency and more elaborate tests of mental processing are required to elucidate the impact of folate metabolism on depressive mood and cognitive function in patients with epilepsy.